Apparatus for gripping sheet material



Aug. 8, 1967 w. R. CONNER. JR 3,334,500

APPARATUS FOR GRVIPPINC SHEET MATERIAL 5 Sheets-Sheet l Filed DeCA 1961 f 0%@ MM5/M Aug. 8, 1967 WR. coNNER, JR

` APPARATUS 'FOR GRIPPING SHEET MATERIAL 5 Sheets-Sheet 2 Filed Deo. 1961 Aug. 8, 1967 W. R. CONNER, JR

APPARATUS FOR GRIPPlNG SHEET MATERlAL 5 Sheets-Sheet 5 Filed Dec.

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@fama/ff Aug- 8, 1957 w. R. CONNER, .1R 3,334,600

APPARATUS FOR 'Q'RIPPNG SHEET MATERIAL 5 sneetssneet 4 Filed DeC. 1.1, 1951 AMag. 8, 1967 W. R. CONNER, JR 3,334,6@0

APPARATUS FOR CIRIPFLNG SHEET MATERIAL Filed Dec. Q, 1961 5 Sheets-$heet 5 /n s mw n, M mmm: um R. /M w #m L Q m irc: s||l l In E m ofimv mm mw www m fr WGW ,www SW @w1 mw M M www www. m @NW1 WNW.. J. im QW. il.. F] mmh. M W www www1 r @E 7 kw www www -i United States Patent O 3 334 600 APPARATUS FOR GRIPPING SHEET MATERIAL William R. Conner, Jr., Shelbyville, Tenn., assignor to Red Kap, Inc., Nashville, Tenn., a corporation of Delaware Filed Dec. 5, 1961, Ser. No. 157,149 7 Claims. (Cl. 112-2) The present invention relates to a novel method and apparatus for feeding and positioning successive portions of a workpiece at a work station, and more specifically to a novel method and apparatus for feeding and positioning a eXible sheet material or fabric.

While various applications for features of the present invention will suggest themselves, disclosure of the invention will be facilitated by describing an embodiment e-specially suitable for use in positioning a fabric article, such as a shirt, so that buttons may be secured thereto or buttonholes may be formed therein. Sewing machines are available which` are capable of substantially automatically sewing buttons on a shirt or of forming buttonholes after the shirt is properly located. Heretofore, it has been the general practice for a workman to position a shirt by hand so that the button or buttonhole is sewn at a desired location and upon completion of the sewing operation the workman moves and repositions the shirt by hand for enabling successive buttons or button-holes to be sewn. This hand feeding and positioning operation is relatively slow. Furthermore, it requires the use of highly skilled labor and even then the buttons or buttonholes are frequently inaccurately located.

An important object of the present invention is to provide a novel method and apparatus for feeding and locating sheet materi-al or fabric articles such as shirts and the like so that successive predetermined areas thereof may be rapidly and accurately positioned at a predetermined work station.

A more specific object of the present invention is to provide a novel method and apparatus for processing fabric articles suc-h as shirts whereby such shirts may be automatically fed rapidly and with precision so as to position successive increments thereof for the sewing of a buttonhole or button in a manner which promotes the manufacture of an improved article or shirt more economically.

A further specific object of the present invention is to provide a novel apparatus capable of feeding and positioning an article such as a shirt and further capable of being used in association with a variety of presently available workpiece processing units such as buttonhole sewing machines or button attaching machines.

A further object of the present invention is to provide a novel method and apparatus for processing articles such as shirts and the like and for enabling the use of relatively unskilled labor.

Still another specilic object of the present invention is to provide a novel machine or apparatus for processing articles .such as shirts and the like, which machine is constructed so as to enable a single operator to control a plurality of yseparate workpiece or shirt processing units of the machine.

Other objects and advantages of the present invention will become apparent from the following description and the accompanying drawings wherein:

FIG. 1 is an elevational view showing an apparatus incorporating features of the present invention; i

FIG. 2 is an enlarged fragmentary sectional view taken -along line 2 2 in FIG. l;

FIG. 3 is a plan view of the apparatus shown in FIG. l;

FIG. 4 is a fragmentary sectional view taken generally along line 4-4 in FIG. l;

3,334,600 Patented Aug. 8, 1967 FIG. 5 is a fragmentary sectional view taken generally -along line 5-5 in FIG. l;

FIG. 6 is a right-hand end elevational view of the apparatus shown in FIG. 1;

FIG. 7 is a sectional view taken generally along line 7-7 in FIG. l;

FIG. 8 is a fragmentary plan view showing an article or -a shirt which may be processed in accordance with the present invention;

FIG. 9 is a perspective View showing an article gripping unit of the apparatus of the present invention;

FIG. l() is an enlarged fragmentary sectional view taken generally along line 10-10 in FIG. l;

FIG. 11 is a wiring diagram for the apparatus of the present invention; and

FIG. l2 is a simplied plan view showing an apparatus incorporating additional features of the present invention.

Referring now more specifically to the drawings wherein like parts are designated by the same numerals throughout the various figures, an apparatus 20 incorporating features of the present invention is shown in FIGS. l and 3. The apparatus 20 comprises a unit 22 which is shown in simplified form and which may, for example, be a buttonhole sewing or button applying unit of various known constructions. Mounted in association with the unit 22 is feeding and positioning means 24 which is adapted to support a fabric workpiece or shirt 26 and automatically position successive predetermined points 28, 30, 32 and 34 thereof at work station 36 in the manner described in detail below. As indicated in FIG. 8, the workpiece 26 may be processed so that buttonholes 38 are formed therein at the aforementioned predetermined spaced points thereon.

The feeding and positioning means 24 comprises a horizontally disposed tubular frame memrber 40 having opposite ends connected to brackets 42 and 44 which in turn are mounted on a suitable support 46. The support 46 may :be Xed or it may be movable as will be `described more in detail below. As shown in FIGS. 1, 3 and 4, parallel rods 48 and 50 are disposed along opposite sides of the frame member 40. The rod 48 has its opposite ends supported by Ibrackets 52 and 54 which are welded or otherwise secured to the frame member 40, and the rod 50 is similarly supported by brackets 56 and 58 fixed to the frame member. A

Slide or carriage means is mounted on the guide bars 48 and 50. This means comprises bearings 60, 62 and 64 providing a three point support for an L-shaped member 66 which is secured to a sleeve 68 carried Iby the bearing elements 60 and 62 and another sleeve 70 surrounding the bearing element 64. An elongated horizontally disposed bar '72 is secured on top of the L-shaped member 66 as shown best in FIGS. 3 and 5. An elongated notched bar 74 which is shown best in FIG. 4 is secured beneath and movable with the L-shaped member 66 and serves a function discussed hereinbelow.

Workpiece gripping units 76 and 78 are respectively mounted on opposite end portions of the carriage bar 72. As shown in FIGS. l and 9, screws 80 and 82 extend through a :base member 84 of the unit 76 and cooperate with a clamping member 86 disposedwithin the tubular carriage bar 72 (see FIGS. l, 6 and 7) for securing the unit 76 in position. As shown best in FIG. 5, the carriage bar 72 is provided with an elongated slot 88 through which the screw elements 80 and 82 extend which slot permits the unit 76 to 'be adjusted longitudinally of the carriage bar. The unit 7S is provided with identical clamping means for sec-uring it to an opposite end of the carriage bar which is also slotted as at 90, which clamping means need not be described in detail.

As shown best in FIGS. 1 and 9, the unit 76 includes a. pair of upstanding resilient or flexure spring members 92 and 94 respectively having their lower ends secured to opposite ends of the block 96 which in turn is fixed to the base member 84. Upper ends of the flexure elements are respectively secured to opposite ends of a generally horizontally disposed block 98.

An elongated and slotted plate 100 is adjustably secured on top of the block 98 by means of screws 102, which plate carries upstanding ears 104 and 106 in which a shaft 108 is journalled. A gripper jaw lmember 110 1s fixed on one end of the shaft 108 and carries a gripper pad 112 adapted to cooperate with an oppositely disposed xed gripper pad 114 which is soldered or otherwise secured to the plate member 100.

In order to actuate the shaft 108 and thus the gripper pad 112, a lever 116 is fixed to the shaft and extends laterally for connection with a plunger 118 of a solenoid 120 mounted `on a bracket 122 which in turn is fixed to the plate member 100. As shown in FIGS. 6 and 9, a spring 124 isconnected between the outer end of the lever 116 and a post 126 which extends upwardly from a connection with the Ibracket 122. The spring 124 biases the lever 116 in a counterclockwise direction as viewed in FIG. 6 so that the gripper pad 112 is normally urged to a closed article gripping position. When, however, the solenoid 120 is energized, the lever 116 is pulled downwardly to the position shown in FIG. 6 so that the gripping pad is pivoted to the open position.

When it is desired to insert an article such as a shirt to be processed between the gripping pads 112 and 114, the solenoid 120 is energized so that the pad 112 is raised or opened. Then one end of the shirt, usually the collar end, is inserted between the pads 112 and 114. A suitable guide element 128 is fixed to the plate member 100 and is formed so as to conform to a portion of the article such as the ycollar of a shirt whereby to facilitate proper positioning of the article ybetween the pads 112 and 114. After the article has 4been positioned between the pads 112 and 114 the solenoid 120 is deenergized and the spring 124 serves to clamp the pad 112 downwardly.

When the article or shirt 26 is secured between the gripping units 76 and 78, it is stretched or drawn to a substantially taut condition by the operator for promoting accurate positioning of the aforementioned predetermined points along the shirt at the working station during the subsequent processing operation. However, when buttonholes are to be formed or other sewing operations are to be carried out, it is frequently necessary that the material of the article 26 be in a slack condition so that it may be properly manipulated yby the sewing or processing unit 22. In order to provide slack in the article or material being processed, the gripping unit 76 is constructed for enabling the gripper pads 112 and 114 to be shifted as a unit toward the gripping unit 718. Thus, as previously indicated, the upstanding members 92 and 94 are in the form of flexure springs and means are provided for locating the members 92 and 94 in the substantially straight upstanding positions shown and for flexing the members toward the unit 78. Thus, a solenoid 130 having a plunger 132 is mounted on a spacer 134 which in turn is fixed on the -block 96. The solenoid and plunger are formed so that the plunger is free to move to the position shown in FIGS. 1 and 9 when the solenoid is deenergized but `cannot move farther toward the right, and the plunger is adapted to *be shifted toward the left as viewed in FIGS. 1 and 9 when the solenoid is energized. A tension spring 136 is `connected between the bracket 138 fixed to the spacer 134 and a pin 140 secured to and `depending from the block 98. As shown in FIG. 1, the pin 140 is adapted to Ibear against one end of the plunger 132 while an opposite end of the plunger is adapted to engage a spring finger 142 fixed on the upstanding spring element 92. When the solenoid 130 is deenergized, the spring 136 serves to pull the pin 140 and thus the gripper pads 112 and 114 toward the right as viewed in FIG. 1 until stopped by the plunger 132. When the solenoid is energized, the plunger shifts toward the left as viewed in FIG. l and pushes the finger against the action of the spring 136 so as to shift the gripper pads 112 and 114 toward the left.

The gripper unit 78 is essentially identical to the unit 76 and therefore need not be described in detail. It suffices to state that the unit '78 includes a solenoid 144 corresponding to the above described solenoid 120` for opening and closing the gripper pads of the unit 78. In addition the unit 78 includes a solenoid 146 corresponding to the previously mentioned solenoid 136 for controlling shifting of the gripper pads of the unit 78 toward and away from the unit 76.

In order to feed and position the aforementioned carriage means and gripper units 76 and 78 with respect to the unit 22 and work station 36, a drive chain 148 is provided, which chain encircles sprockets and 152 respectively mounted on shafts 154 and 156. Opposite ends of the chain are connected at 158 and 160 to the bearing sleeve 70 as shown in FIGS. l and 3. The shaft 156 is preferably carried by an adjustably mounted slide 162 so that the tension in the chain may be controlled.

A sprocket 164 is fixed `on the shaft 154, which sprocket is driven by an endless chain 166 .that extends from a transmission or drive and brake unit 168. The chain 166 extends around and is driven by a sprocket 170 fixed on an output shaft 172' of the unit 168. A gear 174 fixed on the shaft 172 is driven by a pinion 176 which in turn is fixed on a rotatable shaft 178. A first clutch disc is fixed on the shaft 178 and a second clutch disc 182 is carried Iby a sleeve 184 mounted on the shaft 178 for rotation with the shaft but axially movable relative to the shaft. A spring 186 is compressed between the bottom of a bore provided in the shaft 178 and an end of the sleeve 184 for normally biasing 4the friction disc 182 toward brake or friction elements 188 fixed on a wall of the housing 189 of the unit 168.

A pulley 190 is disposed on the shaft 178 between the friction discs 180 and 182, which pulley is freely rotatable relative to the shaft and carries friction or clutch elements 192 projecting from opposite sides thereof and engageable with the friction discs 180 and 182. The pulley 190 is driven by an endless belt 194 which in turn is adapted to be driven by a pulley 196 on an output shaft of an electric motor 198 or any other suitable prime mover.

The motor 198 is of a type which may be electrically reversed and is preferably driven continuously during a work-piece processing operation. However, the shaft 178 is normally held against rotation yby engagement of the friction disc 182 with the brake elements 188. When it is desired to drive the shaft 178, the friction disc 182 is shifted axially against the action of the spring 186 sufficiently to cause the friction or clutch elements 192 on the pulley 190 to be clamped between the friction discs 180 and 182. In order to accomplish such axial shifting of the friction 0r combined clutch and brake plate 182, a solenoid 200 is provided, which solenoid is adapted to actuate a plunger 202 downwardly as viewed in FIG. 10. The plunger 202 is connected with one end of a cross head-204 which has an opposite end slidably mounted on a rod 206 and resiliently biased downwardly as viewed in FIG. 10 by spring 208. A ball bearing element 210 is interposed between complementary seats on the cross head 204 and the end `of the sleeve 184 for transferring the thrust between the cross head and the sleeve. The spring 208 is of insufficient strength to function by itself to overcome the force of the spring 186, but the spring 208 does provide a force which may be adjusted by turn ing the nuts 212 on the post or rod 206 and which 'therefore combines with the solenoid 200 to provide an adjustable force for urging the friction disc 182 into effective engagement with the clutch elements on the pulley.

While 4the carriage is adapted to be intermittently driven and stopped by the clutch and brake unit 168, means is provided for positively stopping and locating the carriage means in a predetermined manner so that each of the aforementioned points on the article or shirt will be accurately located at the work station. T'he stop and locating means includes the previously mentioned bar 74 which is shown best in FIG. 4 and which is secured beneath the L-shaped member 66 of the carriage. Notches 214 are formed in a margin of the bar 74 at predetermined intervals. It is to be noted Ithat each of the notches merges with a gradually inclined surface 216 which precedes the notch in the direction of movement of the bar 74 during a work processing operation. A pawl 218 is iixed on a shaft 220 for cooperative engagement with the abutment or stop surfaces provided by the notches 214. The shaft 220 is rotatably mounted with respect to the fixed frame member 40 and extends through the frame member so that an upper end thereof which carries the pawl 218 is located above the frame member and a lower end thereof projects beneath the frame member. A lever arm 222 is connected with lower end of the shaft 220 as shown in FIGS. l and 4. A spring 224 is connected between an -outer end of the lever 222 and a pin 226 xed to and depending from the frame member 40 so as to bias the shaft 220 in a clockwise direction as viewed in FIG. 4 and urge the pawl 218i for entry into the notches 214.

In order to retract the pawl 218 from a notch 214 when it is desired to move the carriage means, a solenoid 226 is provided as shown in FIG. 1. The solenoid includes a plunger 228 adapted to be pulled toward the left `as viewed in FIG. l when the solenoid is energized. The plunger 228 is connected by link means 230 with a rod 232 which in turn is connected with an outer end of the lever 222 so as to pivot the shaft 220 in a counterclockwise direction as viewed in FIG. 4 when the solenoid 226 is energized.

It will be appreciated that various electrical circuits and related components may be provided for controlling the sewing or processing head or unit 22, the electric motor 198 and the previously described solenoids, or in other words, for controlling the overaall operation of the zapparatus. One such control circuit is shown in simplified form FIG. 1l.

The control circuit comprises means for enabling an operator to energize the solenoids 120 and 144 for opening the grippers and permitting the article to be positioned therebetween. This means comprises a switch 240 which, ttor example, is in the form of a foot pedal operated switch. The switch 240 is connected in a wire 242 which extends between a power line L-1 and an elongated fixed contact or wire 244 disposed beneath the carriage of the feeding and positioning means. As shown in FIGS. 1, 2 and 11, additional elongated contacts or wires 246 and 248 are disposed parallel to the wire 244 and all of these elongated contacts or wires are mounted in grooves provided in an elongated Iblock 250 of insulating material disposed beneath the aforementioned carriage means. Movable contacts 252, 254 and 256 respectively engage the wires 244, 246 and 248. The movable contacts are carried by a cross head 258 secured to the lower end of a member 260 which is secured to and depends from the carriage bar 72 as shown in FIGS. l, 2 and 7. The sliding contact 252 is connected with first terminals of the solenoids 120 and 144 by a wire 262 and suitable branch wires 264 and 266. Second terminals of the solenoids 120 and 144 are connected with the sliding contact 254 by a wire 268 and branch wires 270 and 272. The elongated fixed wire or contact 246 is connected with a power line L-2 by a wire 274 so that when the switch 240 is closed, the circuit for energizing the solenoids 120 and 144 will be completed.

As previously indicated, the solenoids and 146 which control the slack or tension in the article ybeing processed aredeenergized during insertion of the article between the grippers and during feeding movement of the article and are energized only during each successive sewing or processing operation. Thus, the control circuit for energizing and deenergizing the solenoids 130 and 146 includes a switch 276 which is responsive to and actuated by movement of an element 278 of the sewing head or unit 22. While the element 278 may be various parts of the sewing head mechanism and will vary depending on the specic sewing or processing unit used, it is usually a standard part of such mechanism and therefore need not be described in detail. It suffices to state that the element 278 is such as to move in a manner for closing the switch 276 when the sewing or other processing operation is started and for opening the switch .276 when the sewing or other processing operation is completed. For example, the unit 22 is shown as including a pressure pad or foot 280 which, as will be understood, is lowered against the article when a sewing operation is to be commenced and is raised when the sewing operation is iinished. When such a mechanism is used, it is contemplated that the element 278 will close the switch 276 when the foot 280 is lowered and will open th-e switch when the lfoot 280 is raised.

The switch 276 has one terminal connected by Wire 282 with the power line L-1 and another terminal connected by wire 284 with the elongated fixed contact or wire 248. As previously indicated, the wire 248 is engaged by the sliding contact 256. This contact is connected by a wire 286 and suitable branch wires 288 and 290 with rst terminals of the solenoids 130 and 146. Second terminals of these solenoids are connected by branch wires 292 and 294 with the previously mentioned Wires 270 and 272 which are connected with the power line lf2 through the sliding contact 256 and the xed elongated contact 246. It is thus seen that when the switch 276 is closed upon the starting of a sewing or processing operation, the solenoids 130 and 146 will be energized for relaxing the tension in the article 26.

The electric circuit includes a control panel 296 connected with power lines L-l, L-2 and L-3 by wires 298, 300 and 302 and further connected with the reversible motor 198 by wires 304, 306 and 308. The control panel includes switches 310 and 312 of any suitable construction which are manually operable for respectively starting and stopping the motor 198. The control panel is also connected by wires 314 and 316 with the sewing head or processing unit 22 which, as will be understood, includes selfdcontained power and control means that function automatically to start and complete a sewing or processing operation when the power circuit including the wires 314 and 316 is energized. The control panel 296 is provided with a switch 318 of suitable construction which may be manually operated for energizing the portion of the circuit including the wires 314 and 316 and thereby starting the initial sewing or processing operation.

When processing an article in accordance with the present invention, the switch 240 is first closed and the article is inserted between the grippers and preferably manually stretched to a relatively taut condition whereupon the switch 240 is opened so that the article will be clamped by the grippers. Then the switch 310 is manually operated for starting the motor 198 in. a forward direction. The motor operates continuously during processing of the article, but theV carriage means initially remains xed since the solenoid 200 is deenergized and the clutch mechanism is not engaged. Then the switch 318 is manually closed for energizing the unit 22 and initating the first sewing or processing step. When this occurs the switch 276 is closed as previously described and the tension in the article is relieved. Upon completion of the sewing or processing step, the switch 276 is opened so that tension is restored to the article and the solenoids 200 and 226 are energized for respectively engaging the clutch mechanism for driving the carriage means and for releasing the latch member 218 for permitting the carriage means to advance.

In order to energize the solenoids d) and 226 at the proper time, a switch 320 is provided in association with the unit 22, which switch is adapted to be closed upon completion of the sewing or processing operation. In the specific embodiment shown, the switch 320 is associated with the switch 276 and is also adapted to Ibe actuated by the element 278. The arrangement is such that when the element 278 moves in one direction, the switch 276 is closed and when the element 278 moves in an opposite direction the switch 320 is closed. The switch 320 is connected by wires 322 and 324 with the control panel 296 and more specifically with suitable relays in the control panel which serve to energize the solenoids 200 and 226 when the switch 320 is closed. The relay which controls the solenoid 204) may be of known construction and is adapted to maintain the solenoid 200 in an energized condition until another switch 326 is opened. The switch 326 is connected with the control panel by wires 328 and 330 and is associated with the linkage means 230 between the plunger 228 of the solenoid 226 and the latch control rod 232. The arrangement is such that when the control rod 232 and the linkage means 230 return toward their normal or retracted position in the manner described more in detail below, the switch 326 will be opened for deenergizing the solenoid 200 and thereby causing the clutch means of the mechanism 168 to be disengaged and the brake means of this mechanism to be engaged.

The relay in the control panel 296 associated with the solenoid 226 is also of known construction and is such as to energize the solenoid 226 only for a suicient length of time to enable feeding movement of the carriage to be initiated and for then deenergizing the solenoid 226. With this arrangement it is seen that when the switch 320 is closed at the completion of a sewing or processing step, the solenoid 200 will be energized to start feeding movement of the carriage means and the solenoid 226 will be energized for retracting the latch 218 from the notch 214 for permitting such feeding movement. After initial feeding movement of the carriage is accomplished, the solenoid 226 is deenergized so that the latch element 218 tends to rotate in a clockwise direction as viewed in FIG. 4. As a result, the end -of the latch or pawl 218 bears against an edge portion 332 of the bar 74. This prevents the latch or pawl from pivoting and therefore prevents the connecting rod 232 and the link 230 from returning toward their deenergized position whereby the link means maintains the switch 326 closed. As feeding movement of the carriage means continues, the end of the pawl or latch element 218 will eventually ride on one of the inclined or cam surfaces 216 which merge with the surface or edge portions 332. Continued movement of the carriage means and thus the bar 74 causes the inclined surface 216 to permit the latch or pawl element 218 to pivot in a clockwise direction as viewed in FIG. 4 for enabling the connecting rod and link means 230 progressively to return toward their retracted position. The arrangement of the inclined surfaces 216, the link means 230 and switch 326 is such that the switch 326 will be opened at a predetermined instant slightly before the en-d of the pawl or latch element 216 drops into a notch 214. Inertia in the system will cause the carriage means to continue to advance until the end of the pawl is fully engaged in the next notch 214, but at the same time, the clutc-h mechanism will be disengaged and the brake means of the unit 168 will be engaged for helping to stop the carriage lmeans and preventing undue shocks from arising within the apparatus which might otherwise result if the carriage means were abruptly stopped upon engagement of the latch element or pawl with the abutment surfaces provided by at notch 214.

When a feeding step has been completed and the latch or pawl element is again fully seated within the next notch 214, suitable relay means within the control panel 296 functions to again energize the unit 22 for starting the next sewing or processing step. It will be appreciated that the cycle may be repeated as many times as desired within the limits of the apparatus. At the completion of the desired successive sewing or processing steps, the carriage means is advanced until a pin or cam element 334 fixed to a base portion of the gripper unit 78 as shown in FIGS. 1 and ll, engages a limit switch 336 which is suitably fixed and mounted at a desired location. The switch 336 is connected by wires 338 and 340 with relay means within the control panel 296, which relay means serves electrically to reverse the motor 198 for driving the carriage means back toward its original or starting position. When the carriage means reaches its fully retracted or starting position, suitably located and fixed switches 342 and 344 are actuated by pin or cam elements 346 and 348 respectively carried by the base means of the gripper unit 76 as shown in FIGS. 1 and l1. The switch 342 is connected with the control panel by wires 350 and 352 and serves to actuate relays within the control panel for deenergizing the solenoid 288 and for preventing the unit 22 from being energized until the manual control switch 318 is again operated. The switch 344 is connected with the control panel by means of wires 354 and 356 and serves to operate the motor controlling relay so that the motor is again electrically reversed for operating in the normal or forward direction. As a final step in the processing operation, t-he operator closes the switch 248 for opening the grippers whereupon the article is removed and replaced by another article to be processed.

As previously indicated, the apparatus 20 may be mounted on a suitable xed support. However, in accordance with another feature of the present invention it is contemplated that a plurality of the apparatus or machines Ztl may be mounted on a movable support structure for successive movement to a predetermined work station for enabling a single operator to load and unload and otherwise control all of such machines. Thus, as shown in simplified form in FIG. l2, a plurality of the apparatus or machines 20 may be mounted on a rotatably supported turntable 358 for successive movement past a work station 360. Any suitable means may be provided for rotating the turntable 358 at the desired speed and for intermittently stopping the turntable for a predetermined interval after each successive machine 20 arrives at the work station 360. Such drive means may include a sprocket 362 fixed on the rotatable shaft 364 which supports the table. A chain 366 encircles the sprocket 362 and another sprocket 368 xed on a suitably supported shaft 370 which also carries a bevel gear 372. The gear 372 is driven by a gear 374 on an output shaft of a transmission 376 which is capable of intermittently driving the gear 374 at the desired speed. An electric motor 378 or other suitable prime mover may be provided for driving the transmission 376.

While the preferred embodiments of the present invention have been Shown and described herein, it is obvious that many details may be changed without departing `from the spirit and scope of the appended claims.

The invention is claimed as follows:

1. An apparatus for processing an article of flexible material of the type described comprising a unit for performing work on said article, means for continuously gripping spaced apart portions of said article and for supporting said article adjacent said unit, means for relatively intermittently moving said unit and said support means a predetermined distance for presenting successive portions of said article to said unit, and means for tensioning said article during relative movement of said unit and said support means and for relieving tension in said article while the article is being worked upon by said unit while continuously gripping said spaced apart portions, said support means comprising spaced apart gripping units adapted to grip an article arranged therebetween and generally upstanding flexible support members respectively supporting said gripper units and adapted to be flexed toward and away from each other, and said means for relieving the tension in the article and for tensioning said article includes means for moving said gripper units toward and away from each other.

2. An apparatus, as defined in claim 1, wherein said means for tensioning said article comprises spring means for biasing said gripper units relatively away from each other.

3. In an apparatus of the type described, the combination comprising conveying means, a pair of spaced apart gripping means mounted on said conveying means for continuously clamping and retaining and supporting an article of flexible material to be processed therebetween, means for intermittently feeding said conveying means during predetermined increments and advancing successive portions of said article to a predetermined work station, and means for moving at least one of said gripping means relative to said conveying means and toward the other of said gripping means during intervals between feeding movements of said conveying means for imparting slack to said article and for moving said one gripping means relative to the conveying means and away from said other gripping means for tensioning said article during feeding movements of said conveying means, said one gripping means comprising a base, a self-supporting flexible member having one end secured to said base and at opposite ends spaced laterally from said base, and a pair of cooperable gripper elements operatively supported on said opposite end, said flexible element being adapted to be bent toward and away from said other gripping means.

4. Sheet material work holding apparatus comprising,

(a) needle means,

(b) means for selectively actuating said needle means to operate on said work,

(c) a carriage,

(d) a pair of clamping devices mounted longitudinally on said said carriage on opposite sides of said needle means,

(e) each clamping device comprising a pair of clamprng jaws,

(f) means for moving each pair of jaws toward each other to hold work therebetween and away from each other to release said work,

(g) means for moving said clamping devices toward each other to a work slack position simultaneously with the actuation of said needle means to operate on said work, and for moving said clamping devices .away from each other to a work tension position when said needle means is inoperative,

(h) means for moving said carriage longitudinally, while said needle means is inoperative and said clamping jaws are closed on said work, to position said work for operation thereon by said needle means at selectively different stations,

(i) indexing means for automatically locking said carriage at said stations and simultaneously actuating said needle means for operation and said means for moving said clamping devices to slack position,

(j) said indexing means comprises a latch and an elongated bar longitudinally fixed to said carriage and having longitudinally spacedl notches, there being a notch for each station, means for pivotally mounting said latch in a stationary position relative to the movement of said carriage, and means for actuating said latch to selectively engage each successive notch during the longitudinal movement of said carriage.

5. An apparatus for processing an article of liexible material of the type described comprising a unit for performing work on said article, means for supporting said article adjacent said unit, means for relatively intermittently moving said unit and said support means a predetermined distance for presenting successive portions of said article to said unit, and means for tensioning said article during relative movement of Isaid unit and said support means and for relieving tension in said article while the article is being worked upon by said unit while continuously gripping said spaced apart portions, wherein said support means comprises spaced apart gripper units adapted to grip an article arranged therebetween, and said means for relieving the tension in the article and for tensioning said article includes means for moving said gripper units toward and away from each other, wherein each of said gripper units comprises a pair of gripper elements relatively movable toward and away from each other, solenoid means for moving said gripper elements away from each other, and spring means for biasing said gripper elements toward each other when the solenoid means is deenergized,

`6. An Vapparatus for processing an article of exible material comprising:

(a) a unit for performing work on said article,

(b) means for selectively operating said unit,

(c) a pair of clamping devices on opposite sides of said unit for holding said work in position for operation thereon by said unit,

(d) each clamping device comprising a pair of opposed jaws,

(e) means for selectively closing each pair of jaws to hold -said work, and opening said jaws to release said work,

(f) solenoid means for simultaneously moving each of said clamping devices toward each other to a position wherein the work held thereby is in a slack condition, when said solenoid means is energized, and simultaneously with the operation of said unit on said work,

(g) spring means for simultaneously moving said clamping devices away from each other to a work tensioning position when said solenoid means is deenergized and while said unit is inoperative, and

(h) means for moving said work, while said unit is inoperative, to selectively different positions for operation thereon by said unit.

7. An lapparatus for processing an article of flexiblematerial comprising:

(a) a unit for performing work on said article,

(b) means for selectively operating said unit,

(c) a carriage,

(d) a pair of clamping devices mounted longitudinally on said carriage on opposite sides of said unit for holding said work in position for operation thereon by said unit,

(e) each clamping device comprising a pair of opposed Jaws,

(f) means for selectively closing each pair of jaws to hold said work, and opening said jaws to release said work,

(g) means for simultaneously moving each of said clamping devices toward each other to a position wherein the work held thereby is in a slack condition simultaneously with the operation of said unit on said work, and for simultaneously moving said clamping devices away from each other to a work tensioning position while said unit is inoperative,

(h) means for moving said carriage longitudinally, while said unit is inoperative and said clamping jaws are closed on said work, to position said work for operation thereon by lsaid unit at selectively different stations,

(i) said carriage moving means comprising a motor, clutch means and brake means, means for actuating said clutch means and de-actuating said brake means to connect said motor to said carriage for moving said carriage, and means for de-actuating said clutch means and actuating said brake means and actuating said brake means to disconnect said motor from said carriage and to stop said carriage at one of said stations.

References Cited UNITED STATES PATENTS Allen 112-2 Stull 269-153 X Allen 112-76 Kiewicz 11275 Allen 112--76 Baader 198--209 X Myska 112-67 Gardner 112-2 X McGill 112-67 X 12 Zeitlin 112-2 X Kelemencky 112--2 McBean et al. 112- 2 X Reeber et a1 112-2 Troll et al 112--2 OTHER REFERENCES German printed application No. 1,069,070, 11-1959.

Examiners.

S. G. LAYTON, R. V. SLOAN, I. R. BOLER,

Assistant Examiners. 

1. AN APPARATUS FOR PROCESSING AN ARTICLE OF FLEXIBLE MATERIAL OF THE TYPE DESCRIBED COMPRISING A UNIT FOR PERFORMING WORK ON SAID ARTICLE, MEANS FOR CONTINUOUSLY GRIPPING SPACED APART PORTIONS OF SAID ARTICLE AND FOR SUPPORTING SAID ARTICLE ADJACENT SAID UNIT, MEANS FOR RELATIVELY INTERMITTENTLY MOVING SAID UNIT AND SAID SUPPORT MEANS A PREDETERMINED DISTANCE FOR PRESENTING SUCCESSIVE PORTIONS OF SAID ARTICLE TO SAID UNIT, AND MEANS FOR TENSIONING SAID ARTICLE DURING RELATIVE MOVEMENT OF SAID UNIT AND SAID SUPPORT MEANS AND FOR RELIEVING TENSION IN SAID ARTICLE WHILE THE ARTICLE IS BEING WORKED UPON BY SAID UNIT 